I just finished this book last night and read most of it in the last week. It centers around Jake, a schoolteacher in 2011, who finds out through a local diner owner, Al, that there is what is termed a "rabbit hole" in the back of his restaurant that takes people to 1958. Al is dying from lung cancer and has Jake go through the rabbit hole a couple of times to experience it before telling him his idea: Al wants Jake to go and live in the past and prevent JFK's assassination. Initially, Jake doesn't think he's up to it, but eventually agrees to Al's persuasion. Al gives Jake money, a fake ID (Jake becomes "George"), and a notebook he has written on Oswald and his movements in Dallas leading up to the assassination. Jake takes all of this information with him and tries to lead as normal of a life as possible in the past, but doesn't always quite blend in due to some catchphrases that don't exist yet, which makes some people suspicious. I think how King blended everything together worked well, but I will admit I was disappointed by the ending.